Oxide-Based Complementary Inverters With High Gain and Nanowatt Power Consumption

Oxide semiconductors are ideal candidates for flexible and transparent electronics. Here, we report complementary inverters based on p-type tin monoxide and n-type indium–gallium–zinc-oxide thin-film transistors. The inverters have a gain of 63 at a supply voltage, ${V}_{\text{DD}}$ , of 1.5 V with a maximum static power consumption of 15.6 nW, and a gain of 226 at ${V}_{\text{DD}}$ of 3.0 V with a maximum power consumption of 241.2 nW. A five-stage ring oscillator (RO) based on the complementary inverters is able to operate at 1.04 kHz with full amplitude oscillations at ${V}_{\text{DD}}$ of 1.5 V. All the inverters and RO are fabricated on silicon wafers but at a maximum processing temperature of 225 °C, so that the results are relevant to possible flexible applications. The extremely low power consumption of nanowatt, high gain, kHz operation, and possible flexibility of the fabricated complementary components is well suited to meet the requirements of wearable electronics, Internet of Things technology, and so on.